Spark plug



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Dec. E8, W23.

T. P. PETERSON SPARK PLUG Filed Nov. '2. 1920 Harri J 1 iii? WRWWV/I VQ w v a Patented Dec. l8, W23.

SPARK PLWG' Application filed November 2, 19530. ficrial 25o. tlfilfiltlil To all whom it may concern:

Be it known that I, Trwononn P. PETER- soN, a citizen of the United States, residing at \Vessington Springs, in the county of Jerauld and State of South Dakota, have invented certain new and useful Improvements in Spark Plugs, of which the followin; is a specification.

This invention relates to spark plugs for igniting the combustible charges in the power cylinders of internal combustionengines; and it consists in the novel construction and combination of the parts hereinafter fullydescribcd and claimed.

ln the drawings, Figure l is a vertical section. through a spark plug constructed according to this invention and drawn to a greatly enlarged size for clearness. Fig. 2 is a plan View, taken in section on the line 22 in Fig. 1. Fig. 3 is a similar section, taken on the line 3-3 in Fig. 1.

The body screwthrcaded portion (5 for connecting it to the engine cylinder in the usual way. A chamber 7 is formed in the upper part oi the plug body, and is closed by a cap 8. The cap 8 has a screwthreaded portion 9 for securing it to the plug body, and 10 is a packing washer for keeping it gas tight. The cap 8 may however be secured in any other approved Way.

llod electrodes 12 are provided, and are arranged symmetrically my the chamber with their lower end portions, projecting from it- .Three electrodes are shown, ar ranged in triangular form, but two electrodes may be used, or as many more than three as may be found advantageous. The electrodes 12 have oilset upper-end portions 14 which are secured in tapering shanks 15, These shanks 15 are secured in tapering insulators 16 of any approved insulating material, and may be used for that purpose. The up per end portions of the shanks and the tubular insulators project through tapering holes in the cap 8, and are secured in e block 1? of insulating material.

The block 17 is preferably formed of u series of thin plates of mice. The shanks and insulators are anchored in the block by means of projecting plates 18 secured to the tops of the shanks by nuts 19 or other fastening devices. The anchor plate 18" of portion 5 of the plug has a stern ot:

the clue on its up er one shank is provided with a which projects centrally from has a screwthreaded portion 2 part.

A washer plate 24% rests on the top- L of mica, and the plates of mice. are held place by a nut on the screwthreuded tion 2i which is connected to one line wire 26 by a nut 52?. The other line wire nected with the plug body. trode 30 is secured to the plug; bod oy stem: 31, encircles the end porti i o the rod electrodes so that three are formed in the exai'nple Sl'lOWll, and or included in the electric circuit between th wire 26 and the plug body. The sparkformed in all of these spark ZLQSlSL in igniting the combustible mixture in cylinder, so that the se ne is ig'i'iited eilectively.

ln carrying out the invention the various parts are proportioneoi so to make as little waste space sspossihle in the chamber 7, the proportions in the drawings being arranged so us to show the ports as clearly cs possible. The object using a ring elec trode on the plug body is to insure spark gap between one of the rod electrodes irre spective of the position to which the supportinc; cap is screwed totlie plug; body.

l fhst ll claim is:

in s sperlr plug, e. plug body, a l311OV-- closing the top of the plug body, an ted rod electrode projecting through the said cap and provided'with means which prevent itifrom sliding; upwnrdly, said rod electroi e being adapted to form a spark gap at the lower part of the plug body. a block formed of thin superposed pistes of insulat ingrnaterial resting on the said cap, onohor plate incloscd in the said block and secured to the rod electrode lie-vin scr-cwtln'ceded block a wire, a nut screwed on the SQCllZ'lllg'E; the rod electrode and s to the cup. 7

2. .ln sparl: plug, a plug; body, ring; electrode secured at lower part thereof, a removable cap closing the top of the plug body, insulated rod electrodes which spark gaps with each other with ring electrode, sold electrodes project m to ltltl through the said cap and provided with stem which projects from the block and afmeans which prevent them from sliding; upfords a connection for the line Wire, and a wardly, a block formed of thin superposed nut screwed on the said stem and securing 10 plates of insulating material resting on the the rod eie ctrodes'and the block to the cap.

6 said cap, anchor plates inclosed in the said In testimony whereof I have aflixed my block and secured to the rod electrodes, one signature. of the anchor plates having a screwthreaded THEODORE P. PETERSON. 

